<template>
  <div class="msite">
    <!--首页头部-->
    <HeaderTop :title="address.name">
      <router-link  class="header_search" slot="left" to='/search'>
        <i class="iconfont icon-sousuo"></i>
      </router-link>

      <router-link  class="header_login" slot="right" :to="userInfo._id ? '/userInfo' : '/login' ">
        <span class="header_login_text" v-if="!userInfo._id">登录|注册</span>
        <i class="iconfont icon-person" v-else></i>
      </router-link>
    </HeaderTop>
    <!--首页导航-->
    <nav class="msite_nav">
      <div class="swiper-container" v-if="categorys.length">
           
        <div class=" swiper-wrapper">
          <div
            class="swiper-slide"
            v-for="(categorys, index) in categorysArr"
            :key="index"
          >
            <a
              href="javascript:"
              class="link_to_food"
              v-for="(category, index) in categorys"
              :key="index"
            >
              <div class="food_container">
                <img :src="baseImageUrl+ category.image_url" />
              </div>
              <span>{{category.title}}</span>
            </a>
          </div>
        </div>
        <!-- Add Pagination -->
        <div class="swiper-pagination"></div>
      </div>
      <img src="./images\msite_back.svg" alt="back" v-else>
    </nav>
    <!--首页附近商家-->
    <div class="msite_shop_list">
      <div class="shop_header">
        <i class="iconfont icon-xuanxiang"></i>
        <span class="shop_header_title">附近商家</span>
      </div>
      <ShopList />
    </div>
  </div>
</template>


<script>
import { mapState } from "vuex";
import HeaderTop from "../../components/HeaderTop/HeaderTop.vue";
import Swiper from "swiper";
import "swiper/dist/css/swiper.min.css";

import ShopList from "../../components/ShopList/ShopList.vue";
export default {

   data(){
       return{
        baseImageUrl:'https://fuss10.elemecdn.com'
       }
   },
  mounted() {
    this.$store.dispatch("getCategorys");
    this.$store.dispatch("getShops"); //获取商家列表

   
  },

  computed: {
    ...mapState(["address", "categorys","userInfo"]),
    //根据categorys 一维数组生成一个二维数组，小数组中的元素个数最大个数是8个
    categorysArr() {
      const { categorys } = this;
      // 准备一个空的二维数组
      const arr = [];
      let minArr = [];

      //遍历categorys
      categorys.forEach((c) => {
        //如果当前小数组已经满了，创建一个新的数组
        if (minArr.length === 8) {
          minArr = [];
        }
        //当前如果minArr 是空的，将小数组保存到大数组中
        if (minArr.length === 0) {
          arr.push(minArr);
        }

        //将当前分类保存到小数组中
        minArr.push(c);
      });

      return arr;
    },
  },

  watch :{
     categorys (value){ //说明数组中有数据了，在异步更新界面之前

    //  //使用setTimeout可以实现效果
    //  setTimeout(() => {
    //          //创建一个swiper对象，来实现轮播
    //   new Swiper(".swiper-container", {
    //   loop: true, //可以循环轮播
    //   // 如果需要分页器
    //   pagination: {
    //     el: ".swiper-pagination",
    //     clickable: true,
    //   },
    // });
      
    //  }, 100);

     //希望界面更新就立即创建swiper对象
     this.$nextTick(()=>{ //一旦完成界面更新立即调用（此条语句放在数据更新之后）
      new Swiper(".swiper-container", {
       loop: true, //可以循环轮播
      // 如果需要分页器
       pagination: {
        el: ".swiper-pagination",
        clickable: true,
      },
    });

     })


     }
  },
  components: {
    HeaderTop,
    ShopList,
  },
};
</script>

<style lang='scss' scope slot-scope>
@import "../../common/style/style.scss";
.msite {
  width: 100%;
}

.msite_nav {
  position: relative;
  margin-top: 45px;
  height: 200px;
  background: #fff;
}
.msite_nav::before {
  content: "";
  position: absolute;
  z-index: 200;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 1px;
  background-color: #e4e4e4;
  transform: scaleY(0.5);
}
.msite_nav .swiper-container {
  width: 100%;
  height: 100%;
}
.msite_nav .swiper-container .swiper-wrapper {
  width: 100%;
  height: 100%;
}
.msite_nav .swiper-container .swiper-wrapper .swiper-slide {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  flex-wrap: wrap;
}
.msite_nav .swiper-container .swiper-wrapper .swiper-slide .link_to_food {
  width: 25%;
}
.msite_nav
  .swiper-container
  .swiper-wrapper
  .swiper-slide
  .link_to_food
  .food_container {
  display: block;
  width: 100%;
  text-align: center;
  padding-bottom: 10px;
  font-size: 0;
}
.msite_nav
  .swiper-container
  .swiper-wrapper
  .swiper-slide
  .link_to_food
  .food_container
  img {
  display: inline-block;
  width: 50px;
  height: 50px;
}
.msite_nav .swiper-container .swiper-wrapper .swiper-slide .link_to_food span {
  display: block;
  width: 100%;
  text-align: center;
  font-size: 13px;
  color: #666;
}
.msite_nav
  .swiper-container
  .swiper-pagination
  > span.swiper-pagination-bullet-active {
  background: #02a774;
}
.msite_shop_list {
  position: relative;
  margin .msite_shop_list::before {
    content: "";
    position: absolute;
    z-index: 200;
    left: 0;
    top: 0;
    width: 100%;
    height: 1px;
    background-color: #e4e4e4;
  }
}
.msite_shop_list .shop_header {
  padding: 10px 10px 0;
}
.msite_shop_list .shop_header .shop_icon {
  margin-left: 5px;
  color: #999;
}
.msite_shop_list .shop_header .shop_header_title {
  color: #999;
  font-size: 14px;
  line-height: 20px;
}
</style>